Rice is an annual cereal grass widely grown in warm climates for its seeds and used for food and for its by-products (Webster's Ninth New Collegiate ).Rice is classified among cereals and shares equal importance as a major food source with wheat. Rice is a staple food for more than half of the world's population. Rice grows on every continent in the world except Antarctica. There are 21 different known wild varieties and three distinct cultivated species. Oryza sativa japonica is believed to have been domesticated in what is now central China around 7,000 BC (Hirst). This crop has been grown in more than 100 countries, covering an area from a latitude of 53° north to 35° south. About 95 percent of the world's rice is grown and consumed in Asia. The highest level of per capita rice consumption (130 to 180 kilograms [kg] per year, or 55 to 80 percent of the total calorie source) is in Bangladesh, Cambodia, Indonesia, Laos, Myanmar (Burma), Thailand and Vietnam (Kiple and Ornelas). Today, rice accounts for about 20 percent of the world's total calorie intake. Rice is not only a staple in diets around the world, but it also occupies a central place in the economy and landscape of ancient and modern Asian civilizations. Mainly unlike Mediterranean crops, which are mainly based on wheat (Hirst). On the international market, the price of rice is higher than that of wheat. However, less than five percent of the world's rice enters the commercial market, compared to about 16 percent of the world's harvested wheat. In low-income countries, such as China and Pakistan, they are often able to export their rice at a higher cost than it would take to import wheat (Kiple and Ornelas). Rice has become a middle of paper. .....created. The East Asia Rice Working Group, for example, was established with the aim of exempting rice from trade liberalization (the rice industry). Since the dawn of civilization, rice has been a vital grain for humans in humid regions of Asia and, to a lesser extent, in West Africa. The introduction of rice to Europe and the Americas led to its increased use in human food. In the eastern half of Asia, where 90 to 95 percent of rice produced is consumed locally, cereals are the largest source of total dietary energy. In 2000, about 40 percent of the world's population, primarily in the most populous and least developed countries, relied on rice as their primary source of energy. The question, of course, is whether rice-producing countries, with continued technological advancement, can maintain production levels above population growth (Kiple and Ornelas).)